The present invention relates in general to overhead (bridge) crane systems and in particular, to a mechanism for interlocking an end of a movable track with an aligned end of a stationary track. The invention is especially directed toward a completely mechanical interlocking mechanism suitable for use in shipboard environments where it may be subjected to strong vibration and high intensity shock.
In material handling apparatus, overhead cranes are frequently provided with a carrier rail extending transversely to the direction of movement of the crane. This rail is commonly employed to support a movable hoist which may carry a load suspended therefrom. As the crane moves along its path of travel, the carrier rail comes into alignment with one or more stationary tracks which lead to other parts of the work area or other crane tracks.
Various devices have been proposed for locking a movable carrier rail to a stationary rail when the two are in aligned position. One type of mechanical hoist stop system, referred to as "paddle stops", operates automatically at each crossover position to raise the stops and permit passage of the hoist. This mechanism has the disadvantage that it does not prevent traversing a crane away from the crossover when a hoist is transfering on or off a crane. It also experiences a high wear rate as the stops are automatically cycled every time rails pass or stops align, whether or not hoist transfer is desired. In a second type of mechanical stop system, the "Richard Wilcox" type, stops are manually operated to extend a probe that automatically raises the stops when the crane is properly aligned at the crossover. This mechanism also permits traversing a crane away from the crossover during hoist transfer if the probe is manually released. Furthermore, most previous devices are not suitable for shipboard environments and in particular are not suitable for combat conditions.